Rotary shearing head



Aug- 19, 1941. H. L. COLLINS 2,253,016

ROTARY SHEARING- HEAD Filed May 18, 1938 0722062250? @2 02: CbflzI zs M la UNI-TED STATES PATENT- OFFICE v 2.253.016 r I I ROTARY SHEABJNG HEAD. Harry L. Collins, St. Louis; Mo., assignor to r Knapp-Monarch Company, StVLouis, Mo., a corporation of Missouri I Application May 18, 1938, Serial No. 208,644 1 Claim. mums) An object of my invention is to providea very simple rotary shearing head involving a minimum number of working parts, and utilizing centrifugal force to maintain shearing contact be- I tween inner cutter blades andan' outer cutter ing head comprises an outer cylinder C, a body member 13 and shearing plates I 5. The outer cylinder C has a flared portion l6. adapted to fit the neck l3 and is normally retained in position relative thereto by a spring-pressed ball H. The

spring is indicated at 18 and the ball is adapted v to ent'era socket I9 formed in'the cylinder as comprising an outercylinder perforated to recomprising an outercylinder mounted on the motor over the motor shaft and an inner cutter having a body member provided with substantially radially extending slots in which cutter blades are slidably mounted for shearing coaction with the inner surface of the outer cylinder.

Withthese and other objects in view my invention consists in the construction, arrangement and combination of the various parts of my shearing head, whereby the objects contemplated are attained, as hereinafter more fully .set forth, pointed out in my claim, and illustrated in the accompanying. drawing, in which:

Figure l is a side elevation of a rotary shearing v. head embodying my invention and showing it mounted on a motor.

Figure 2 is an enlarged sectional view on the line 2-2 of Figure 1. Figure 3 is a sectional view on the line 3--3 of Figure 2. p v

Figure 4 is a perspective view of the body member and cutter blades of my shearing head.

Figure 5 is a side elevation of a modified form of structure; and

Figure 6 is a sectional view on the line 6--6 of Figure 5. I

On the accompanying drawing I have used the reference character M to indicate a motor such as the small type adapted to be used as a handle for dry shavers as now in general use. The motor M is supplied with electric current from a plug l0 and supply cord I! in a'well-known manner, which requires no specific description as it forms no part of mypresentinvention.

The motor housing M has a neck. I3 on its up-' per end on which I mount my rotary shearing head. The motor has a shaft l4 journaled in the neck I3 and extending from the upper end of the neck as shown in Figure 3. My. rotary shearshown in Figure 3.

The body member Bhas a bore 20 receiving the motor shaft I4. The body member may be secured to the motor shaft in any suitable manner such as by a pin 2!. The body member B has slots 22 which slidably receive the blades l5.

vTwo of the slots are illustrated although one,

be accomplished by forming its interior surface off center relative to its outer surface. This results in different portions of the cylinder permitting reception of the hair to different depths.

For instance at the point I) in Figure 2 a very 1 close shave can be secured as the thickness of this portion of the cylinder wall is minimum. At 0, d, and e, progressively greater thicknesses of the wall permit less extension of the hair through the cylinder C and consequently a less close shave.

The hair which is clipped off is expelled through an opening 24 in theupper end of the cylinder C so as to prevent the hair from clogging the interior of the shearing head to such an extent that it will not operate.

v During operation the blades l5, since they are 'free to slide in the slots 22, will be urged outwardly by centrifugal force into shearing engagement with the inner surface of the cylinder C. Such centrifugal force results from rapid rotation of the motor shaft M which preferably rotates at a relatively high speed (about 7000 R. P. M.). The centrifugal action therefore eliminates the necessity of any spring means or other mechanism to maintain shearing contact during operation of the shearing head.

As shown in Figure 5 the cylinder C has a bulge riphery of the cylinder to secure the desired type of shave during operation of the shearing head.

As above pointed out, centrifugal force produced by rotation of the shearing motor results in the elimination of auxiliary means to bias the blades to engage the outer cylinder. The speed of rotation can be varied to vary the degree of shearing contact pressure between the blades and the cylinder and the operator is always insured that good contact will be maintained without danger of spring breakage or other trouble.

Some changes may be made in the construction and arrangement of the parts of my device without departing from the real spirit and purpose of my invention. Accordingly I intend to cover by my claim, any modified forms of structure or use of mechanical equivalents which may be reasonably included within their scope.

I claim as my invention:

In a shearing device, the combination of a support, a housing supported thereby and roan internal surface formed as a right circula cylinder and having an outer surface forme substantially as a'. right circular cylinder, said cylinders being formed on offset parallel axes. the resulting relatively thin portion of said housing being apertured to form a skin-contact shear plate, said rotating cutter means comprising a body element having radially extending slots therein, and cutter blades freely slidable in said slots, each of said cutter blades consisting tating cutter means therein, said housing having of a generally rectangular block having a straight line cutting edge, and having said cutting edge extending longitudinally of said housing and engaging with the inner surface thereof when said cutter means is rapidly rotated; an opening in the outer end of said housing, and means in said support for rapidly rotating said cutter means on the axis of the inner surface of said housing.

HARRY L coums. 

